Method of shrinking and felting animal fibers



Patented Sept. 10, 1929.

PATENT OFFICE.-

JOHN H. MARTIN, OF BALDWIIV, NEW YORK.

METHOD OF SHRINKING AND FELTING ANIMAL FIBERS.

No Drawing. Application filed February 7, 1928, Serial No. 252,686. Renewed January 31, 1929.

In the treatment of animal fibers, such as fur, hair or wool, in which the fibers are shrunken and felted together, as for example in themanufacture of felt hats, the fibers,

after having been subjected to a preliminary treatment, such as carroting, and massed together, as by being blown upon a form, are subjected to a shrinking and felting operation carried on in the presence of a liquor which may be, for example, pure water slightly acidulated. It has been proposed heretofore to promote the shrinking and felting by the addition to the liquor in the presence of which the operation is carried 1 on of a relatively small quantity of a bisulphite. The use of bisulphites, however, has not proved to be wholly satisfactory in practice for the reason that bisulphites have a tendency to soften the fibers, and sometimes 2 to have an unfavorable action on the dyestuffs employed, and generally to have a deleterious effect upon the workmen as well as upon the metal parts of the apparatus employed by reason of decomposition of the bi- 2 sulphites in hot solutions and the release of free sulphur dioxide fumes.

In accordance with the present invention, however, it has been found that the undesirable effects of bisulphites are overcome and the process of felting the fibers is promoted by the use of a condensation product of sulphur dioxide or a bisulphite with an aldehyde such, for example, as formaldehyde. In the practice of the method the sulphur dioxide or a bisulphite is condensed with an aldehyde, such as formaldehyde, in the manner well known to chemists of producing a condensation product, and of such condensation product a quantity which may vary somewhat with the nature of the fiber to be felted, or with its intended use, but is relatively small as compared by weight with the weight of the fiber under treatment, is added to the liquor in the presence of which the shrinking and felting operation is carried on in the usual manner. It is found that the resultant felt is considerably smoother and tighter when treated in this manner than is the case if the same material is treated without the condensation product,

Furthermore, the condensation product has no unfavorable effect upon the color, which oftentimes is brightened considerably and appears to be faster to light. Again, the release of deleterious fumes does not occur.

It has been found that the use of sulphur dioxide or bisulphite leads to a wasting of the substance of the fibers and that the use of a condensation product. as described, inhibits the hydrolysis of the fibers and prevents such wasting of their substance.

The use of acondensation product of a bisulphite with an aldehyde is claimed in a separate application filed concurrently herewith.

I claim as my invention:

1. The improvement in the method of shrinking and felting animal fibers in the presence of a liquor which consists in the addition to such liquor of the condensation product of a sulphur dioxide with an aldehyde.

2. The improvement in the method of shrinking and felting animal fibers in the presence of a liquor which consists in the addition to such liquor of the condensation product of sulphur dioxide with formaldehyde.

This specification signed this 3d day of February A. D. 1928.

JOHN H. MARTIN. 

